In a series of published biographical statements stretching back for years -- including his bio on Yahoo's website -- Thompson has said that he "holds a Bachelor's degree in accounting and computer science" from Stonehill College.

But his degree is actually only in accounting, a fact Third Point discovered and pointed out in a scathing letter to Yahoo's board of directors.

After the letter was released, Yahoo (YHOO, Fortune 500) sent out a statement saying references to Thompson earning a computer science degree were an "inadvertent error."

It's an error Thompson made repeatedly. References to Thompson's nonexistent computer science degree are featured in his bios on sites for PayPal, the eBay (EBAY, Fortune 500) subsidiary where he previously served as president.

Stonehill, a small Roman Catholic college in Massachusetts, also confirmed to CNNMoney that Thompson's only degree is in accounting.

Third Point called Yahoo's response "inadequate" in a Friday statement: "To assert that years of inaccurate SEC filings, website biographies and [more] ... were 'inadvertent' is, in our view, the height of arrogance."

Third Point wants the Yahoo board to fire Thompson for cause, and to take three other major actions by noon on Monday: Reveal the vetting process for Thompson's appointment as CEO, explain the process for nominating board directors, and disclose whether any Yahoo board members knew about Thompson's college degree inaccuracy.

Yahoo, which quickly stripped all references to Thompson's degree out of his official bio on Yahoo's website, said the error "in no way alters that fact that Mr. Thompson is a highly qualified executive with a successful track record leading large consumer technology companies."

Yahoo updated its statement late Thursday to add that its board will be reviewing the issue and will, when that probe is completed, "make an appropriate disclosure to shareholders."

Dan Loeb, the CEO of Third Point, has a long history of launching proxy fights -- and Yahoo is the latest company in his crosshairs. In February, Third Point filed paperwork proposing four new Yahoo board members, including Loeb himself.

Yahoo doesn't want to play ball, and Third Point's subsequent proxy letters have been filled with vitriol.

One choice line from Thursday's letter: "We learned that during Mr. Thompson's tenure at Stonehill only one such course was even offered -- Intro to Computer Science. Presumably, Mr. Thompson took that course."